Of ten “vulnerable groups” examined in the University of Utah-led study, only AIDS patients used doctor-assisted suicide at elevated rates. The research deals with the so-called “slippery slope” argument that has been made by critics of doctor-assisted suicide and has raised concern. The argument is that by making it legal for medical doctors to help certain patients end their lives, vulnerable people will die in disproportionately large numbers.

“Would these patients be pressured, manipulated or forced to request or accept physician-assisted dying by overburdened family members, callous physicians, or institutions or insurers concerned about their own profits"” the researchers asked. They looked at two places where it is legal for doctors to help patients end their lives.

In Oregon the law allows doctors to prescribe lethal medications to patients who have been diagnosed by two physicians as having a terminal illness and less than six months to live. In the first nine years after the law took effect, 456 patients received lethal prescriptions and 292 of those actually used the drugs to kill themselves. That is 0.15 percent of all deaths in Oregon during the same period.

In the Netherlands a law allows doctors to prescribe medication for suicide or perform “voluntary active euthanasia,” in which the physician administers life-ending medication. Dutch law does not require terminal illness, but “you have to be facing intolerable suffering,” bioethicist Margaret Battin, a University of Utah distinguished professor of philosophy and adjunct professor of internal medicine says.

Of 136,000 deaths annually in the Netherlands, about 1.7 percent are by voluntary active euthanasia, 0.1 percent by physician-assisted suicide and 0.4 percent are “extralegal” because they involve patients with no current explicit request to die, but who either made one before becoming incompetent or are perceived to be suffering intolerably.

The researchers found direct evidence that elderly people, women and uninsured people do not die in disproportionate numbers where physician-assisted death is legal, but AIDS patients do. They also found evidence that is partly direct and partly inferred showing that physician-assisted death does not kill disproportionate numbers of people who are poor, uneducated, racial and ethnic minorities, minors, or people with chronic physical or mental disabilities or chronic but not terminal illnesses. The researchers noted that in both Oregon and the Netherlands, people who received a doctor’s help in dying averaged 70 years old, and 80 percent were cancer patients.